Activated high specific surface area carbon aerogels for EDLCs

This paper shows that the performance of resorcinol–formaldehyde-based carbon aerogels in electrical double-layer capacitors (EDLCs) can be significantly enhanced by a simple treatment with CO2 activation. The changes in the specific surface area lead to high capacitance values, which provide a noticeable energy density. The CO2 activated carbon aerogels have a high specific surface area up to 3431 m2/g and specific capacitances three times higher than that of the raw carbon aerogels. The activated carbon aerogels obtained the specific capacitance at 152 F/g and energy density of 27.5 Wh/kg at the current density of 0.3 A/g in 1 M Et4NBF4–AN electrolyte. Furthermore, an excellent rate capability, low equivalent series resistance (ESR), and a good cycling stability over 8000 cycles of the resulting carbon aerogels were also confirmed by electrochemical measurements as galvanostatic charge–discharge, cyclic voltammetry and electrochemical impedance spectroscopy.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The CO2 activated carbon aerogels have a high specific surface area up to 3431 m2/g. ► Specific capacitances are three times higher than that of the raw carbon aerogels. ► Obtained the specific capacitance at 152 F/g and energy density of 27.5 Wh/kg. ► A good cycling stability over 8000 cycles.